Unstable pelvic fractures typically occur as a result of high-energy injuries such as automobile accidents, falls and the like. Even in this age of modern polytrauma care, acute pelvic fractures are potentially lethal. In the past, such injuries were treated without surgery. However, recovery to completely normal functionality was the exception rather than the norm. In more modern times, unstable pelvic fractures are treated surgically with a number of techniques depending on the type and extent of the fracture(s).
The pelvis consists of three major bones (two ilium and the sacrum) and some minor bones joined together in a ring shape and held by strong ligaments, See FIG. 1. General characteristics of pelvic fracture include severe pain, pelvic bone instability, and associated internal bleeding. Devices and methods used to treat fracture of the pelvis currently fall under two general classifications; internal fixation and external fixation. Combinations of both techniques are frequently chosen for certain fracture patterns.
Internal fixation is typically utilized when the patient exhibits unstable posterior pelvic fractures. Internal fixation refers to plates and screws applied directly onto the fracture sites after realignment. See, for example, U.S. Pat. Nos. 4,454,876; 5,108,397; 6,340,362 and 6,440,131. This type of fracture tends to be more complex with it involving multiple bony structures. Internal fixation addresses these clinical issues through open reduction and correction of misaligned bone segments that are subsequently stabilized with a wide variety of plate and screw methods.
Anterior pelvic fractures or hemodynamically unstable patients are candidates for external fixation. Pelvic external fixation consists of pins usually inserted into the iliac bones and then connected together by clamps and bars. See, for example, U.S. Pat. Nos. 4,292,964; 4,361,144; 5,350,378 and 6,162,222. External fixation methods consists of stabilizing the pelvic ring with a rigid framework residing outside the patient's body that is connected to the patient's pelvis via multiple pins that penetrate through the patient's soft and hard tissues. Several frame types are currently utilized. Two of the more widely deployed devices for external pelvic stabilization are the Hoffmann 2 Inverted “A” Frame and the Ganz Pelvic C Clamp.
The application of external reduction and fixation for pelvic fractures is advantageous compared to internal reduction and fixation due to its speed of deployment and lower level of technical training required for utilization. The primary disadvantages of external fixation of pelvic fractures include high risk of pin tract infections, and general patient discomfort. Also, the external frame physically blocks subsequent surgery on the abdomen and they are frequently difficult to fit to obese patients.
The instant inventor has developed a novel method using the already established principles of anterior external fixation. By combining these principles with internal hardware placed in a minimally invasive fashion, this technique allows for definitive pelvic stabilization without having the issues and co-morbidities of an external fixator (i.e. interfering with other procedures, pin care, patient acceptance, later conversion to internal fixation, etc.)
The pelvic ring can also be rendered incompetent by other mechanisms such as tumors which are benign or malignant that destroy the pelvic bones. Infections or the subsequent treatment of infections which requires the removal of pelvic bone, from osteolysis after total hip arthroplasty due to wear debris and an inflammatory response or due to a congenital malformation can also render the pelvic ring unstable. In these situations if the acetabulum is lost, it would be useful to perform a total hip arthroplasty and to reconnect the limb to the remaining bone of the pelvis or the spine. Further, when repairing a pelvic injury with a severe acetabular injury, it would be useful to perform a total hip arthroplasty. This is particularly the case when there is significant involvement of cancer in the acetabulum and other critical mechanical portions of the pelvis. The present invention combines the hardware and surgical techniques of minimally invasive treatment of unstable pelvic ring injuries and placement of the acetabular cup assemblies for total hip arthroplasty